Ion-exchange materials are well known for their utilization in the processes of water treatment,1, 2, 3, 4, 5 demineralization,6, 7 water softening,8, 9, 10 ultra purification of water11, 12 and removal of unwanted ions,13, 14 as well as in chemical processing.15 One ion-exchange material is acidic sulfonated polystyrene-divinylbenzene (DVB) cation-exchange resin, which has an important role in the production of bisphenol-A by participating in an acid-catalyzed condensation reaction between phenol and acetone. Bisphenol-A is a very important raw material for the synthesis of epoxy resins and polycarbonates; thus, >400 000 tons of bisphenol-A have recently been domestically produced. However, in the conventional polystyrene-DVB system, despite various improvements, the rate of conversion of acetone to bisphenol-A cannot be maintained owing to deterioration because of a long reaction period.16 This disadvantage could be attributed to the tiny space created by the crosslinkage of the DVB in the polystyrene-DVB system. Such a tiny space might reduce the number of sulfonated groups in the resin and induce the accumulation of by-products. Thus, to increase the conversion of acetone and to increase the space inside the polystyrene resin, divinylnaphthalene (DBN) or divinylbiphenyl (DVBP) will be used in this study as the crosslinking reagent instead of DVB to produce bisphenol-A.

Copolymerization of styrene and crosslinking reagents in the emulsion, followed by sulfonation with sulfuric acid, was performed to give the desired crosslinked polystyrene resins (styrene-DVB, styrene-DVBP and styrene-DBN) according to reported methods.17

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account
Continue with Google
Continue with ORCiD